Risperidone for treatment-refractory major depressive disorder: a randomized trial.

BACKGROUND: Major depressive disorder has high prevalence, morbidity, and mortality. Inadequate results with antidepressants have prompts addition of a nonstandard treatment (augmentation therapy).

OBJECTIVE: To assess whether augmentation therapy with risperidone reduces symptoms and increases response to antidepressant therapy and remission of depression in adults.

DESIGN: Multicenter, double-blind, placebo-controlled, randomized trial conducted from 19 October 2004 to 17 November 2005.

SETTING: 75 primary care and psychiatric centers.

PATIENTS: 274 outpatient adults with major depressive disorder that was suboptimally responsive to antidepressant therapy.

INTERVENTION: After a 4-week run-in period to ensure insufficient response to standard antidepressants, patients were randomly assigned to receive risperidone, 1 mg/d, or placebo for 6 weeks. After 4 weeks, the dosage of risperidone was increased to 2 mg/d in some cases.

MEASUREMENTS: Symptoms were measured by using the 17-item Hamilton Rating Scale for Depression (HRSD-17). Other outcomes were response to therapy, remission of depression, and various clinician- and patient-rated assessments.

RESULTS: Of the intention-to-treat population (268 patients), 81% (111 of 137) who received risperidone and 87.8% (115 of 131) who received placebo completed 6 weeks of double-blind treatment. Mean (+/-SE) HRSD-17 scores improved more in the risperidone augmentation group than in the placebo group (13.4 +/- 0.54 vs. 16.2 +/- 0.53; difference, -2.8 +/- 0.72 [95% CI, -4.2 to -1.4]; P <0.001). More risperidone recipients than placebo recipients experienced remission of depression (24.5% [26 of 106] vs. 10.7% [12 of 112]; P = 0.004) and had a response (46.2% [49 of 106] vs. 29.5% [33 of 112]; P = 0.004). Headache (8.8% of risperidone recipients vs. 14.5% of placebo recipients), somnolence (5.1% vs. 1.5%), and dry mouth (5.1% vs. 0.8%) were the most frequently reported adverse events.

LIMITATIONS: Patients were receiving many different antidepressants, and the duration of augmentation therapy was limited.

CONCLUSION: Risperidone augmentation produced a statistically significant mean reduction in depression symptoms, substantially increased remission and response, and improved other patient- and clinician-rated measures. ClinicalTrials.gov registration number: NCT00095134.